50 / 88
50
Figure 19
.
in the timing and intensity of rainfall, or the period of time
without rain, as well as affecting the quality of water in rivers
and lakes through changes in the timing and volume of peak
discharge and temperature (IPCC, 2007).
Anticipation of more droughts and extreme rainfall events has
impacts for non-existent or old, inadequate wastewater treat-
ment facilities highlighting the need for infrastructure that can
cope with extreme surges of wastewater. Changes in the reli-
ability of the water supply have major impacts on the livelihoods
and health of the poorest communities which rely on rainfall or
surface waters and tend to settle in the available low-lying flood-
exposed land, where floods also spread diseases and cause diar-
rhoea through the flooding of open sewage or inadequate sew-
age infrastructure. Increased capacity to capture and store water,
as well as efficient use of water, and maximizing resources that
are available will be important adaptation strategies.
Increasing pressure on water resources through increasing
populations and more unreliable rainfall has in some regions
pushed the exploitation of groundwater resources as other
sources decline. Eighty per cent of drinking water in Russia
and Europe comes from these slowly repleating resources
(Struckmeier
et al
, 2005).
Asia and the Pacific
Million people
Projection for
Africa
217
239
119
137
133
552
2 110
2050
2025
2010
2 964
West Asia
Europe
Latin America
Caribbean
North
America
Population living in river basins where freshwater withdrawal
exceeds 40 per cent of renewable resources
Population by region was calculated averaging the results forecasted by the scenarios of the GEO-4
report using the WaterGAP modeling.
Source: Fourth Global Environment Outlook (GEO-4 report), UNEP, 2007.